Losing power 6BTA under load

[ALBIN]

Albin 28te 1995

Took it out for the first time in 4 months and ran 5 knots for 1 hour

Then attempted to run WOT and only could go 10 knots at 1600 rpm with throttle down with a LOT of black smoke.

Under no load rpm maxed at usual 2600 rpm with NO smoke.

Then after 20 min at 1300 rpm tried again and ran like a top at 2600 rpm/20 knots.

Fuel filters vs injectors ?

[jleonard]

Black smoke is unburned fuel so I say it is NOT the filters.
It is very rarely injectors.
I would suspect clogged air filter, loose clamp in the compressed air plumbing, maybe something that partially blocked air from getting to the engine compartment, or a blocked aftercooler (esp if it a seawater cooled unit).
Could be a stuck turbocharger. If that's the case look for seawater that backed in via the exhaust or crudded up compressor turbine.
Could also be a dirty bottom/prop causing extreme overload that got cleaned off during the low power run.

[Tuxedo]

If you have the blue boat on the lift in Beresford Creek, it's definitely not a dirty bottom.

My first thought was stuck turbo. Take off the air cleaner and see if it spins freely by hand.

Otherwise, I would suggest you call Antony at Marine Propulsion and have him take a look at it.

[Gunny]

I recommend you check the turbo as it is easy to do. A recent experience for me was the turbo shaft initially binding and then breaking. I will keep it short but one turbo later and I continued my trip to Bimini. Somewhat lighter in the wallet but it sure runs like a sewing machine now!Wish you better luck but do check that turbo.

[ALBIN]

Tuxedo you are correct, I have a clean bottom on Beresford Creek! Jlenorard checked all you suggested and appeared fine. Gunny, also checked turbo and seems to spin better than anything on the boat.
Replaced the old fuel filters->racor and fleetguard and will run under load and check performance.
Thanks for the input
Tim

[jleonard]

also checked turbo and seems to spin better than anything on the boat.
Replaced the old fuel filters->racor and fleetguard and will run under load and check performance.
Thanks for the input
Tim

It could have been stuck before the trip and freed up. If you were getting black smoke then you had plenty of fuel, it was air your engine was not getting.

[ALBIN]

Happened again after sitting for several months a loss of power and black smoke at 1600 rpm with a loss of power.

Answer:
Took off air filter and turbo fan was stuck/bound up.
Worked loose and boat runs like a top.

You guys where dead on, Thanks.

First time it happened it fixed itself but thanks to your insight when it occurred a second time I knew first to look for a stuck turbo!

Tim

[jleonard]

Sounds like the main shaft is "coked" which means the oil has baked on to it from overheating at some point in it's past. This makes the shaft slightly larger in diameter hence it gets stuck inside the main bearing , which is really a bushing.
You might consider taking the turbocharger apart and cleaning/rebuilding it, making sure to remove all the brown coking off the main shaft.
They are not hard to do, I have rebuilt several.
Otherwise, make turning the turbo by hand before starting after sitting idle a routine.
You don't want to make a habit out of billowing out black smoke like that because that means uburned fuel is loading up in the cylinders and sliding into the crankcase, contaminating your oil.
But you know that.